Recorder-reproducer apparatus



June 21, 1955 s. B. SHIELDS RECORDER-REPRODUCER APPARATUS 3 SheetsSheet1 Filed March 11, 1950 urn,

J 21, 1955 G. B. SHIELDS 2,711,104

RECORDER-REPRODUCER APPARATUS Filed March 11, 1950 5 Sheets-Sheet 2 yn6027x767 Jeoyeg zdezzda 29w f M M74 affaz/v/cgybx G. B. SHIELDSRECORDER-REPRODUCER APPARATUS June 21, 1955 3 Sheets-Sheet 3 Filed March11, 1950 jam 7/07 07/ Q/f'mec United States Patent Electric Company,Racine, Wis, a corporation of Dela- 1 ware Application March 11, 1950,Serial No. 149,057

9 Claims. (Cl. 74-472) The present invention relates torecorder-reproducer apparatus and especially apparatus of this typeutilizing an elongated record medium such as a magnetic wire or tape andhas for its primary object the provision of new and improved recordmedium driving apparatus.

Recorder-reproducer apparatus of the type to which the present inventionpertains ordinarily utilizes an elongated record medium in the form ofwire or tape which will hereinafter be referred to as tape foruniformity and simplicity of description. It comes wound upon a supplyspool or reel adapted to he placed on the apparatus and from which it isunwound and wound orreeled upon a take-up reel or spool or rewound uponthe supply spool. In recording or reproducing it is essential that thetape be moved at a constant speed and this is customarily done by whatis called a capstan type of drive. The drive comprises a capstan drivenat a constant speed and against which the tape is held so as to be movedby thescapstan at a constant longitudinal speed when it is desiredeither to record or reproduce. In known types of apparatus the capstanis driven through a flywheel, an idler in continuous driving engagementwith the flywheel, and a motor driven drive pulley in continuousdriving, engagement with the idler.

In the copending application of David J. Munroe, application Serial No.79,663, filed March 4, 1949, there is disclosed an arrangement in whichsuch a drive is utilized. The motor drives a drive pulley, that .is incontinuous driving engagement withv an idler wheel that is in continuousdriving engagement with the flywheel, which forms, in substance, apart-of a capstan assembly. Actually, the idler wheel is mounted upon aspring biased guide plate so that it will be in continuous engagementwith the drive pulley and flywheel, this being desirable because theidler wheel is part of a drive assembly mounted upon an index plate thatis moved into different positions in the selective operation of theapparatus to record, listen, rewind, etc.

In order to provide a more efficient drive, the idler Wheel has at leasta rubber or other resilient frictional driving portion. This iseminently satisfactory but it results in making the drive objectionablynoisy and also has a tendency to detract from the quality of therecording under certain conditions. These disadvantages result from thefact that when the apparatus standsidle for a relatively long time, therubber on the idler wheel cold flows with the result that one or moreflat spots are formed on the idler. These disadvantages are, however,avoided by the present invention, according to which the idler wheel isdisengaged whenever the, driving motor is not supplied with power or notrotating.

It is, accordingly, one of the objects. of the present invention toprovide a new and improved drive for recorder-reproducer apparatus.

A further object of the present invention is the provision of a new andimproved recorder-rcproducer apparatus in which the engagement of anidler wheel is controlled conjointly with the eifectiveness of the driveand, more specifically, the idler wheel is moved to engage driving anddriven members before the driving motor is energized.

Another object of the present invention is the provision of a new andimproved recorder-reproducer apparatus in which the motor energizationand engagement of the drive are conjointly controlled, the drive beingfirst engaged after which the motor is rendered operative so that themoving parts of the apparatus are accelerated gradually. Also, thearrangement is such that the motor is first rendered inoperative andthen the drive is disengaged.

In brief, the present invention avoids creation of flat spots in arubber or other resilient tired driving element, such as an idler wheelinterconnecting a drive pulley and a driven flywheel, by disengaging theidler Wheel, when the drive is rendered inoperative, as when the motoris deenergized. This disengagement is efiected conjointly with thecontrol of supply of energy to the motor which may be readilyaccomplished by control means, such as a motor on-ofl switch. Thearrangement is preferably such, also, that the drive is engaged beforethe motor is energized and is disengaged after the motor is deenergized.The arrangement is also such that it is efiective in the variouspositions of a multi position control mechanism.

Other objects and advantages of the present invention will becomeapparent from the ensuing description of an illustrative embodimentthereof, in the course of which reference is had to the accompanyingdrawings, in which:

Fig. 1 is a fragmentary top plan view, partly broken away, of arecorder-reproducer apparatus embodying the present invention; the viewillustrating the apparatus in an operative condition, i. e., the motorenergized andthe idler wheel engaged so that the drive is effective;

Fig. 2 is a fragmentary vertical cross-sectional view taken along theline 2 2 of Fig. 1;

Fig. 3 is a view similar'to Fig. l but illustrating the motordeenergized and the idler wheel disengaged; and

Fig. 4 is a somewhat diagrammatic and'fragmentary bottom perspectiveview of the apparatus, also with the motor deenergized and the idlerwheel disengaged.

The present invention, as already noted, is applicable torecorder-reproducer apparatus, especiallyv of the type employingmagnetic wire or tape. It relates particularly to the drive and controlof such apparatus, with the. result that an understanding of theinvention does not require the illustration or description of a completeapparatus. For this reason it will'be described in con nection with buta portion of the apparatus, but a portion which will, it is believed,give a complete understanding of the invention, its construction, modeof operation and advantages. This portion of the apparatus with whichthe invention is described is similar to apparatus shown in theaforementioned Munroe application to which reference may be had foradditional details.

The apparatus in conjunction with which the invention is describedincludes a recorder-reproducer 10 having a selectively operable controlknob 12 which is manu aiiy. movable into a number of different positionsto condition the apparatus to (1)'record, (2) listen, (3} stop, and (4)rewind. Associatedwith it is an interlock button 1% which must bedepressed before knob 12'ca-n be moved into its record position, wherebyaccidental operation to this position with attendant undesired erasingis prevented.

The control knob is operatively connected to an index plate 24 movableinto different selected positions corresponding to those of the knob.This connection is effected through a control knob shaft 22.and a gear24 ailixed to the shaft and meshing with gear teeth, 26 at one endof-the index plate. The knob is mounted above a main base plate30'andthe shaft extends below the plate. The index plate, which issomewhat rectangular in shape, is supported for pivotal movement belowthe base plate 30 by a pivot pin 32, shown only in phantom, whichextends a short distance below the base plate. The interlock button 14has associated with it mechanism (not shown) cooperating with a shoulder34 on the index plate to prevent the plate, and the control knob, frombeing moved into the record position unless the button is depressed. Thecontrol knob shaft 22 has a second gear 36 aflixed to it for operating aswitch assembly 33 selectively to establish the requisite circuits forlistening, reproducing, etc.

The apparatus includes tape supply and take-up spools of which only apart associated with the latter is shown, this part being indicated byreference character 40. The tape is selectively driven at a constantspeed in a forward direction in the listen and record positions of thecontrol knob by a capstan type of drive including a flywheel-capstanshaft 42 to which the flywheel 44 is affixed and the lower end or" whichis rotatably supported in a supporting bracket 46 aflixed to the underside of the base plate 30. The capstan has a tape engaging portion abovethe base plate and has associated with it a selectively operable rubbertired pinch roller (not shown) whereby the tape can be held against thecapstan and driven at constant speed. The flywheel is conventionallymade of some heavy metal, such as brass and it has a smooth periphery 48through which it is driven at a constant speed.

The flywheel (and other portions not of importance as far as the presentinvention is concerned) is driven by a motor 50, as of the synchronoustype, mounted upon a mounting plate 52 secured to the underside of theindex plate 20. The motor rotates a driving wheel assembly comprising adrive pulley 54 which may be secured to the motor shaft 56. The pulleymay be of metal and have a smooth peripheral driving portion.

In accordance with present invention, the drive pulley 54 is drivinglyconnected to the flywheel to drive the latter and the capstan in allpositions of the control knob and index plate, but only if the motor isenergized. Assuming for the time being that the motor is energized andthe control knob is in the listen position, as shown in Fig. 1, then anidler wheel 60 is in engagement with both the drive pulley and theflywheel and operatively connects them to render the drive operative. Itremains in engagement with these in the other positions of the indexplate, because it is mounted upon a slidable and angularly movable guideplate 62 which is spring biased to the left, as shown in the variousfigures, by a spring 64 connected at one end to the plate and at itsother end to a post 66 secured to the index plate. The right end ofplate 62 is longitudinally slotted at 68 to provide spaced fingers 70slidably received in a grooved idler guide plate pivot 72 below theindex plate to which it is secured by a pin 74. The idler wheel itselfis journalled upon a shaft 76 secured to an intermediate portion of theidler plate.

The spring 64 thus pulls the plate 62 and idler wheel 60 to the left andin a direction to engage the idler with the drive pulley and flywheeland the idler does so engage the pulley and flywheel in variouspositions of the index plate and control knob. One of the otherpositions of the index plate, the record position, is shown in phantomin Fig. 1. While the motor and drive pulley are shown moving with theindex plate, this is not essential for, if desired, the motor may bestationary.

In order to provide an eflicient drive at least the peripheral portionof the idler wheel should be made of rubber or other resilientfrictional material. In the illustrated construction the wheel comprisesa metal 4 develop in the tire because of cold flow when the apparatusstands unused for longer periods of time.

In order to prevent the development of undesired flats in the idlerwheel, it is moved out of engagement, or at least the biasing pressureis considerably reduced, during those times that the motor isdeenergized. This is preferably accomplished through mechanical linkagemeans operatively connecting the idler wheel with a motor energizationcontrol switch and with means, such as a control member or lever,operable manually to T ment is also such that the motor will bedeenergized prior 7 to disengagement of the drive, whereby the motorinertia is used to assist in braking. T

The control member 88 is illustrated as a lever located above the baseplate and attached to a shaft 90 pivotally mounted upon and extendingbelow the plate. A crank arm 92 is fixedly secured to the lower end ofthe shaft. Its free end is pivotally secured by a pin 94 to an elongatedlink 96 forming part of the linkage mechanism.

The crank arm is movable by the lever 88 between on. and off positionsthat are determined by engagement of the bifurcations 96 and 98 at itsend with the reduced diameter end 99 of shaft 90, as shown in Figs. 1and 3,

respectively. In the off position depicted in Figs. 3 and 4, the link 96is seen to be some distance from switch 86 and its operating member 100so that the switch is open; in the on position of Fig. 1 the member 100has been engaged by the link and operated to close the switch.

The link 96 is operatively connected to the idler guide plate 62 by adouble armed lever 102 pivoted at an intermediate point upon pin 104mounted upon a bracket 106 secured to the index plate 20 as by screws orthe like 107 and depending below the index plate. Onearm 102A of thelever extends generally parallel to the outer end of link 96 andhas itsouter angular end in engage ment with an operating pin 108 secured toone of a pair of spaced arms 110 at the end of the link. These armsdefine a slot 112 slidably receiving a guide post 114 mounted at the endof the bracket 106. The other lever arm of lever 102 is indicated by102B and it extends upwardly toward the index plate (see Figs. 3 and 4),and then angularly toward the idler guide plate, where its end 116cooperates with a dependent lug 118 at the end of one of thebifurcations 70 on the plate. The

guide plate spring 64 holds the plate lug 118 against lever arm 102B inthe OE position of lever 88 whereas. the lug is clear of arm 1023 in theon position so i pin 94, results in the link 96 beingurged toward shaft90 and held with arm 96 or 98 abutting against extension 99 of the shaftin both limit positions. -The spring 120,

thus serves to hold the linkage 84 and lever 88 in either of its limitpositions, the link 96 being operable, in

effect, over-center into two positions wherein it is held by the spring120.

The movement of the index plate into its variousf selected positionswith the lever 88 in either its off or on position does not disturb therelation of the idler wheel relative to the drive pulley and fly wheel.

as well as the guide plate 62, are mountedon the index In the presentembodiment the linkage is indi- Asec-m This, i coupled with theillustrated location of the shaft 90Vand;

This 7 results from the fact that the bracket 106 and lever 1 02,

plate and because the guide post 114 associated with the link 96 islocated substantially at the pivotal axis of the index plate and theoperating pin 108 is located near that axis. There is a slight change inthe tension of spring 120 and in the position of pin 108 relative to thefree end of lever 102A as the position of the index plate changes, butthese do not affect the operation.

The relative strengths of springs 64 and 120 are of no particularmoment, the spring 64 being designed to provide the desired bias forceholding the idler wheel against the drive pulley wheel, while spring 120is of desired strength to hold the link 96 and control lever 88 in itslimit position.

It is believed that the operation of the invention will be clear fromthe foregoing detailed description, but it will be reviewed briefly.Assuming that the recorderreproducer control knob is in the listenposition and the lever 88 is in its off position, then the apparatuswill be in the positions illustrated in Figs. 3 and 4. At this time themotor is deenergized, the switch 86 being open and the circuits andother apparatus are conditioned for performance of the listeningfunction. The idler wheel 80 is out of engagement with the drive pulley54 and fly wheel 44, it being so held by engagement of end portion 116of lever arm 102B with the lug 118 on the idler wheel guide plate 62.The position of the lever arm 102B is determined by engagement of pin108 on link 96 with the other end of lever arm 102A and the position ofthe link is determined by engagement of its bifurcation 96 with thereduced end 99 of the shaft 90 to which the lever 88 is afiixed. Thearrangement is such that the idler wheel remains out of drivingengagement with the drive pulley and fly wheel in the various positionsof the index plate 20 and idler wheel.

When it is desired to initiate operation of the apparatus, the lever 88is operated to its on position. When this is done the crank arm 92rotates pivot pin 94 from the position in which it is shown in Fig. 3 tothe position of Fig. 1. When this occurs, the guide plate lug 118 isfreed from the end 116 of lever arm 102B with the result that spring 64maintains the idler wheel in engagement with the drive pulley and flywheel and in the various positions of the index plate. This engagementof the idler wheel with its associated parts occurs before the switch 86is closed by the link 6 engaging and moving the switch operating member100. As a result, the motor is energized after the drive is madeeffective so that the motor and the driven parts of therecorderreproducer accelerate gradually.

When it is desired to stop the motor, the lever 88 is moved from its onto its oif position. When this is done the motor is first deenergizedbecause link 96 first moves away from the switch operating member 100after which the idler wheel is moved away from the drive pulley and flywheel by movement of the lever arm 102 so that the end portion 116 oflever arm 102B engages lug 118 of the idler guide plate and moves theplate back to the position of Fig. 3.

It will be noted therefore that the present invention provides aconjoint control of the motor energization and effectiveness of thedrive. Also, the idler wheel is moved out of engagement with the drivepulley and fly wheel whenever the motor is stopped so that flat spotsare not created in the rubber driving portion thereof no matter how longthe apparatus stands idle. While the idler is shown as moved entirelyout of engagement in the olf position, it should be understood that thisis not always necessary as the movement could be such as to decrease thepressure on the idler to such an extent that flats are not produced init.

While the present invention has been described in connection with theillustrative details of an embodiment thereof, it should be understoodthat these details are not intended to be illustrative of the inventionexcept in so far as set forth in the accompanying claims.

Having thus described my invention, what I desire tosecure and claim asnew in United Letters'P'atent is:

1. An elongated record medium driving apparatus including recordmediumdriving means comprising a flywheel, a drive pulley spaced fromthe flywheel, an idler whe'el having at least a resilient frictionaldriving portion engageablewith said driving pulley and flywheel, a motorfor driving. said drive pulley, a movable support for said idler wheel,a multip'osi tion index platesupp'orting said movable support andelectromechanical "control means controlling the energiz'ation of saidmotor and effecting the engagement-of said idler wheel with said drivepulley and said flywheel in a plurality of positions of said plate, saidcontrol means including a switch controlling the' energization of saidmotor, a movable mechanical link movable into twopositions tooperatefsaid switch to energiz'e and deenergif'z'e said motor andtoeflct movement of said support and the i dler wheel towardand awayfrom said drive pulley and flywheel.

2. An elongated record'medium driving apparatus including incombination, recordmedium driving means comprising an idler wheel havingat least a resilient frictional driving portion and'a driven element, amovable multi-position index plate, means mo'vably supporting said idlerwheel on said index plate, and means including idler wheel control meansassociated withsaid last mentioned means and controlling the engagementof said idler wheel with said driven element for effecting engagementofsaid idler wheel in a plurality of positions of said index plate.

3. An elongated record medium driving apparatus including incombination, a motor, a drive pulley driven by said motor, a flywheelspaced from said drive pulley, an intermediate idler wheel, meansmovably supporting said idler wheel for movement into and out ofengagement with said drive pulley and flywheel, means including a switchoperating lever for connecting said motor to and from a source of power,and means including a linkage mechanism interconnecting said lever andthe idler wheel supporting means for moving the latter to effectengagement of said idler wheel with said drive pulley and flywheel whenthe motor is energized and for moving said idler wheel away from themwhen the motor is deenergized, the engagement of said idler wheel withsaid drive pulley and said flywheel being effected prior to energizationof said motor, and said movement of the idler wheel away from the drivepulley and flywheel effecting disengagement thereof subsequent todeenergization of said motor.

4. An elongated record medium driving apparatus including a drivepulley, a flywheel spaced from said pulley, an intermediate idler wheel,a slidable guide plate supporting said idler wheel and movable to effectengagement and disengagement of said wheel with said drive pulley andflywheel, spring means biasing said guide plate in a direction to effectengagement of said idler wheel with said pulley and flywheel, and meansincluding a pivotally movable control lever, and a linkage mechanisminterconnecting said control lever and slide plate for controlling theposition of said guide plate, said linkage mechanism including a linkassociated with said control lever and a double armed leverinterconnecting said link and guide plate, a crank arm secured to andmovable with said control lever and pivotally connected to said link,said link having a bifurcated end adjacent said control lever, stopmeans engageable by said end to limit movement of that end of the link,means including spaced fingers at the other end of said link and a guidepin between said fingers for guiding that end of the link, a pin on oneof said fingers, said double armed lever including one arm engageablewith said pin, said guide plate having a lug engageable with the otherarm of said double armed lever, and spring means acting on said firstarm of the lever for biasing the lever and link so that one or the otherof the bifurcations of the link engages said stop means.

5. An apparatus as claimed in claim 4 wherein said drive pulley, idlerguide plate, idler wheel, double armed lever and guide pin are mountedupon a movable index plate.

6. An apparatus as claimed in claim 5 wherein said index plate ispivotally movable about an axis, said guide pin is located substantiallyat said axis, and the pin on said one finger is close to said axis.

7. An elongated record medium driving apparatusineluding in combination,record medium driving means comprising an idler wheel, movable idlerwheel supporting means, a driven element normally out of engagement withsaid idler wheel, means for driving said idler wheel, and meansassociated with said last mentioned means and idler wheel supportingmeans operative to elfect engagement of said idler wheel with saiddriven element and then to render operative said idler wheel drivingmeans. 7

8. An elongated record medium driving apparatus including record mediumdriving means comprising a flywheel, an idler wheel engageable with saidflywheel, a movable idler Wheel supporting plate supporting the Wheel,an index plate movable about a pivot axis supporting said plate, adouble armed pivotally movable lever having one arm operativelyconnected to said supporting plate, a longitudinally and pivotallymovable link associated with the other end of said lever, meansincluding a guide pin located substantially at said pivotal axis forsupporting and guiding said link, means including an operating pin onsaid link located near said pivotal axis for operatively connecting saidlink to said other arm of the lever, and means for operating said linkto move said operating pin into different positions thereby to move saidlever and idler wheel into different positions to effect engagement anddisengagement of the latter with said flywheel. x i

9. An elongated record medium driving apparatus ineluding incombination, record medium driving means comprising an idler wheel,movable idler wheel supporting means, a driven element normally out ofengagement with said idler wheel, an electric motor for driving saididler wheel, a switch controlling the energization 'of said motor, alever for operating said switch and for moving said idler wheelsupporting means, and a two position operating said switch to energizesaid motor and render operative said idler driving means.

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